The ability of a device to perform rate reduction on a compressed stream (such as an MPEG stream) is required in more and more cases, ranging from cable systems to Telco and wireless systems. Usually, the rate is reduced by different methods such as re-quantization, re-encoding and similar. If this doesn't succeed in reducing the bit rate enough, some data may be discarded.
A few different activities are involved in rate reduction—these include buffer analysis, timing decisions, actual reduction and more. The actual reduction of bits is a costly and processing-heavy activity as it usually requires at least partial decoding and encoding.
Expensive resources are allocated for this task in terms of computing power and often real cost. As the need for rate reduction grows, there is a growing need to find cheaper methods of rate reduction of video streams.